<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      padding: 0;
      margin: 0;
      box-sizing: border-box;
    }

    body,
    html {
      width: 100%;
      height: 100%;
      background-color: plum;
    }
  </style>
</head>

<body>
  <div>
    大家好，我是黄色页面了吧
  </div>
</body>

</html>